Osmosis through a semipermeable membrane: effects of
solution concentration on the weight of deshelled eggs
Solutions are liquid monophase homogenous mixtures comprised of a solvent - usually, though not always, the prevalent substance and solute, the less prevalent substance. A dissolved substance will be distributed uniformly throughout the solution, at molecular level. The quantity of solute per unit of solution volume or mass is called concentration. This quantity can be expressed as mass per mass of solution (percentage, g of solute per 100 g of solution) or amount per volume (molarity, mol/dm3).
A semipermeable membrane (or selectively permeable membrane) is a membrane that allows the passage of certain substances between the compartments it divides, while preventing passage of others. If two compartments containing solutions of different concentrations are divided by a semipermeable membrane, the entire system will attempt to reach balance. The solution with the higher concentration of the solute is said to be hypertonic to the other solution, while the solution with the lower concentration is said to be hypotonic. Since the system will attempt to balance out the osmotic pressure at both sides of the membrane, the membrane will allow the passage of the substance it is selective for. This process is known as osmosis and it continues until a balance is reached and both sides of the membrane contain solutions of equal osmotic pressure.
Cell membranes are semipermeable membranes. They are a complicated model, because they allow the cell to maintain constant content of certain solutes, using both passive and active transportation to ensure the precise composition of the cytoplasm. There are many synthetic membranes that a...
... middle of paper ...
... be impossible in the hypotonic solution because the membrane would eventually break), i.e. until the eggs stop losing water and their mass becomes constant.
Conclusion
The experiment shows, qualitatively, that two solutions of different osmotic pressures, separated by a semipermeable membrane, will tend to balance out their tonicity. In this particular instance, an egg placed in a hypertonic solution will lose weight as it loses water, and placed in a hypotonic solution, will gain weight as water passes in.
However, no quantitative assessments are possible from the data obtained in this experiment and further experimentation is needed to address these shortcomings.
References cited
Stegall-Faulk, T. Kulkowski, M., Stewart, W. & Cobb, V. (2014) Biology 2011/2021 Human Anatomy and Physiology Laboratory Manual. Plymouth, MI: Hayden-McNeal Publishing.
1B. Given your knowledge of osmosis, will this cause the cells in the body to increase or decrease in size?
Marieb, E. N., & Hoehn, K. (2013). Human anatomy & physiology (9th ed.). Boston, MA: Pearson.
The purpose of the series of experiments in the lab was to in part one, see the relationship between surface area, volume, and the rate of diffusion, diffusion is the process of substances crossing the cell membrane). In part two it was to create manmade “cells” to help discover hypotonic (when t...
During this experiment Brine Shrimp were placed in four bowls. These four bowls contained 2 cups of either water, vinegar or a water and vinegar solution with 50 shrimp in each. Over a course of 3 hours all of the shrimp in the vinegar mixtures died. Beginning this experiment, the control group, placed in two cups of water moved around the bowl actively. This differentiated from the groups placed in vinegar solutions. These shrimp were placed in one of three bowls. In group 2 the tank consisted of one and a half cups water and a half cup vinegar. The third bowl contained one cup water and one cup vinegar. Lastly, the fourth bowl included two cups of vinegar. The shrimp in the control group were the most active. The shrimp in these bowls moved
Osmosis is a special case of diffusion. It is when the passage of water from a dilute solution moves through a semi-permeable membrane to a more concentrated solution. Selective permeability is whether solutes can cross through a membrane freely or not at all. Plant cells and animal cells differ in that plant cells have a strong cell wall and animal cells do not have cell walls. They both can undergo osmosis and both lose water, however the cell wall of plant cells prevent the cells from bursting whereas animal cells will burst because they have no cell wall.
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
Diffusion is when substances diffuse from areas with many particles of the substance and areas with fewer particles of the substance. Concentration is the amount of substance in an area, which means diffusion is when substances diffus...
Marieb, E.N., Hoehn, K. 2013. Human Anatomy and Physiology. 9th edition. Pearson Education Inc. ISPN-13: 978-0-321-74326-8.
there would be no flow of water into or out of the cell so the cell
Potato cores are made of countless cells. A semi-permeable layer called the cell membrane surrounds each potato cell. The cell membrane acts as a barrier between the cytoplasm and its environment. It also gives the cell its structure. The reason why the cell membrane is semi-permeable is because it is mainly composed of a phospholipid bilayer that only allows non-polar and small molecules to pass through it. Fortunately, the cell membrane also contains many transport proteins that allow charged and larger molecules such as water to move into the cell. Other proteins in the cell membrane include glycoprotein and enzymes which are involved in cellular functions such as recognition of other cells and chemical messaging. Another component of the cell
This occurrence can be explained through the process of osmosis. The increase in mass as well as the increase in turgidity, in the potato tubes immersed in low sodium chloride concentration solutions is understood to be a hypertonic. Since the solution is hypertonic, the water molecules will diffuse into the area of lower water concentration (the potato tube) in order to achieve equilibrium. Alternatively, the decrease in mass in the potato tube submerged in highly concentrated sodium chloride solutions can be explained by its immersion in a hypotonic solution. As sodium chloride solution is less concentrated in water molecules than the potato tubes, the decrease in mass and loss of turgidity results from the net movement of water leaving the potato tube, which is higher in osmotic pressure, and diffusing into the solution.
Marieb, E. N., (2006). Essentials of human anatomy and physiology. San Francisco, CA: Benjamin Cummings.
Every matter is made of molecules and they are always in motion. However, there are different types of movements and one example is osmosis, which is a type of passive transport, meaning that they do not need energy to move areas of high concentration to areas of low concentration. Osmosis is the diffusion of water across a selectively permeable membrane which means that water can go through membranes from areas where there are a lot of water molecules to areas where there are not so many water molecules. Adding on, cells must continue keeping an internal steady state called homeostasis in order to continue performing their functions. A selectively permeable membrane is used to maintain the homeostasis by controlling the movement of materials into and out of the cell as well as telling different substances apart and slowing down or stopping the movement of some substances while allowing others to pass through freely.
All things, living or nonliving, consist of atoms and molecules. These particles are constantly in motion, and this continuous motion allows for the disbursement of molecules, or diffusion. The overall net movement of these molecules will go from areas of higher concentration, to areas of lower concentration. Therefore, following a concentration gradient (Martini). The rate of diffusion of these molecules, in accordance with Fick’s law of diffusion, is directly proportional to the concentration gradient present. However, the concentration gradient is not static and will change over time and with distance, therefore changing the rate of diffusion. It is hypothesized that the two solutions being tested, Methylene Blue and Potassium Permanganate, will begin their initial diffusion in the agar gel at a quick rate, and then progressively regress over the allotted time of 1 hour. Another factors other that will have an effect on rate of diffusion is molecular size. There is a substantial difference in molecular weight between Methylene Blue (320 g/mol) and Potassium Permanganate (158 g/mol). The combined molecules present in Potassium Permanganate are lighter than those in Methylene Blue, and therefore should allow it to diffuse more rapidly.
When doing this experiment I was able to see the effect of different concentrations on the rate of osmosis, each was done by measuring the initial mass and length of the potato cylinder and after osmosis, the results were conducted to show that as the sucrose concentration increases the rate of osmosis also increases as I said in my hypothesis thusly making a direct decrease in mass.